Analysis of the Base of a Solid I-beam Column


Design models of the column base (figures in the circles indicate the numbers of the design sections of the base plate: 1 – wing plate; 2 – base plate)

Objective: Check the mode for calculating base plates

Task: Check the load-bearing capacity of the base plate for the design section No.3.

Source: Steel Structures: Student Handbook / [Kudishin U.I., Belenya E.I., Ignatieva V.S and others] - 13-th ed. rev. - M.: Publishing Center "Academy", 2011. p. 259.

Compliance with the codes: SNiP II-23-81*, SP 16.13330, DBN B.2.6-163:2010.

Initial data file:

6.3.sav; report — Kristall-6.3.doc

Initial data:

σf = 1,19 kN/cm2 = 11,9 MPa Stress under the base plate
Ry = 30 kN/cm2 Steel grade C345
b/a = 480 mm / 82 mm Dimensions of the design section of the base

 

KRISTALL parameters:
Steel:
C345  category 1
Group of structures according to the table 50* of SNiP II-23-81* 3

Importance factor 1
Service factor  1,15

a = 0.082 m
b = 0.48 m
Plate thickness = 4 cm
Load 11.9 N/mm2

Manual calculation (SNiP II-23-81*):

1. Design bending moment acting in the design section of the base plate:

\[ M=0,5\sigma_{f} c^{2}=0,5\cdot 1,19\cdot 8,2^{2}=40,0078 \quad kN/cm. \]

2. Check the bending strength of the base plate (γс = 1,15 – according to the table 6* of SNiP II-23-81*):

\[\frac{6M}{t_{p}^{2} }=\frac{6\cdot 40,0078}{4^{2}}=15,002925 \quad kN/cm^{2} \quad \quad < R_{y} \gamma_{c} =30\cdot 1,15=34,5 \quad kN/cm^{2}. \]

Comparison of solutions:

Factor

Source

Manual calculation

KRISTALL

Deviation from the manual calculation, %

for bending strength of the plate

40/81,45=0,491

15,0029/34,5 =

0,43487

0,435

0,0

Comments:

The service factor of the base plate according to the table 6* of SNiP II-23-81* is not taken into account in the source.